- Thu Dec 15, 2022 12:52 am
#188768
A few months ago a mechanic discovered a leaking transmission overload protection switch leaking through the electrical prongs and into the wiring harness.
Merlin was such a great help via PM on what to do, and how to do it.
His thread is here for the process.
https://rennlist.com/forums/diy-928/...tml?styleid=25
With this thread I am adding more context to his DIY. I ran into an issue where a 36mm socket does not have enough leverage to break the protection switch loose.
Tools you need:
36mm Combination Wrench (Huge for leverage)
Dead Blow Hammer (Breaks the old switch loose)
Drain pan (You can lose up to 1 quart of ATF)
8mm Socket and Wrench (for heat shield screws)
Dow Corning 111 for new o-rings
4 jack stands (all 4 wheels need to be up)
Brake Parts Cleaner for Cleaning grime (if you go OCD like I did and clean everything)
The parts:
140 277 01 51 Spacer Ring To Reaction Valve
016 997 34 48 Transmission O-Ring To Rear Case Plug
005 997 80 48 Transmission O-Ring For Reaction Valve At Band B1
016 997 35 48 Transmission O-Ring For Overload Protection Switch
002 545 45 14 Protection Switch
Background: The transmission overload protection switch was initially used on the Mercedes 722.3 transmission to remove timing during hard downshifts and the upshift from first to second. Since the Porsche A28 automatic transmission shares similar components with Mercedes, you will notice these are MB part numbers and this process is referenced on many Benz forums.
Here is my leak. Pretty obvious what it is:
Merlin was such a great help via PM on what to do, and how to do it.
His thread is here for the process.
https://rennlist.com/forums/diy-928/...tml?styleid=25
With this thread I am adding more context to his DIY. I ran into an issue where a 36mm socket does not have enough leverage to break the protection switch loose.
Tools you need:
36mm Combination Wrench (Huge for leverage)
Dead Blow Hammer (Breaks the old switch loose)
Drain pan (You can lose up to 1 quart of ATF)
8mm Socket and Wrench (for heat shield screws)
Dow Corning 111 for new o-rings
4 jack stands (all 4 wheels need to be up)
Brake Parts Cleaner for Cleaning grime (if you go OCD like I did and clean everything)
The parts:
140 277 01 51 Spacer Ring To Reaction Valve
016 997 34 48 Transmission O-Ring To Rear Case Plug
005 997 80 48 Transmission O-Ring For Reaction Valve At Band B1
016 997 35 48 Transmission O-Ring For Overload Protection Switch
002 545 45 14 Protection Switch
Background: The transmission overload protection switch was initially used on the Mercedes 722.3 transmission to remove timing during hard downshifts and the upshift from first to second. Since the Porsche A28 automatic transmission shares similar components with Mercedes, you will notice these are MB part numbers and this process is referenced on many Benz forums.
Here is my leak. Pretty obvious what it is:
Last edited by Mongo on Thu Dec 15, 2022 10:30 am, edited 1 time in total.
Andy
1987 928 S4 Indischrot - #687
1999 Mercedes CLK430 Brilliant Silber
2003 Mercedes ML350 Alabasterweib
2009 Mercedes E350 Schwarz
2011 Mercedes GL450 Palladium Silver
1987 928 S4 Indischrot - #687
1999 Mercedes CLK430 Brilliant Silber
2003 Mercedes ML350 Alabasterweib
2009 Mercedes E350 Schwarz
2011 Mercedes GL450 Palladium Silver